An automatic transmission includes a shift controller and one or more gear sets. Rotatable input and output members of the transmission are selectively coupled to establish a desired speed ratio, with coupling achieved via hydraulic engagement of one or more friction clutches. Some friction clutches may connect an element of a gear set to a stationary member and thereby operate as a braking clutch, while other friction clutches connect one rotating member to another and thus act as rotating clutches. The clutch apply state of a conventional friction clutch ranges anywhere from fully-applied to fully-released.
In some transmissions, a binary clutch assembly is used in lieu of one of the friction clutches. A binary clutch assembly, such as a dog clutch or a selectable one-way clutch having a freewheeling element, relies on interference rather than friction material to hold torque. Binary clutch assemblies can be used alone or in conjunction with friction clutches to attain certain gear states, e.g., first gear. Unlike conventional friction clutches, a binary clutch assembly has just two possible clutch states: fully-applied and fully-released. When fully applied, the binary clutch assembly cannot rotate in either rotational direction. When released, the binary clutch assembly is able to rotate freely in either/both directions depending on the design.